Athena Big Bore kit fuelling problem

Recently fitted the Athena 170 big bore kit onto my 2005 DT SM/R. Worked beautifully for the first two or three days and now struggles to run. Feels as if there is too much air in the mixture/not enough fuel. Tried the obvious fixes e.g. carb clean, increasing tickover etc. Runs fine with the choke on/whilst using the throttle but cuts out as soon as it’s idling. Anybody else experienced similar issues and have any ideas as to what it could be?